In the smartphone world, Google Inc. and Samsung Electronics Co. have a complex relationship that has made them both close allies and intense competitors.

But in the nascent wearables market, the relationship will be a little more straightforward: both companies have ambitions of being the dominant player when it comes to software and services.

And in the past two days, both sides have been racing to draw the battle lines, eager to stake a claim to the community of third-party developers that could help make or break the two companies’ respective efforts.

That was a marked departure from Samsung’s first-generation Galaxy Gear smartwatch that, like its Galaxy smartphones, was powered by Google’s Android operating system.

Samsung’s new Tizen development kit for wearable devices gives programmers the tools to make the third-party apps that turn the devices into virtual Swiss army knives, with a wide range of functions and applications, from mapping and photo-taking to social media and fitness.

The release of Samsung’s developer kit comes as Google ramps up its efforts to make its own mark on the wearables market. Earlier this month, Google executive Sundar Pichai said that the Mountain View, Calif.-based company would soon release its own software development kit for wearable devices, on an Android-based platform called Android Wear.

While Samsung and Tizen may be first to the punch with a smartwatch and development kit, Android remains the juggernaut in the developer community, with a deep reservoir of interest and expertise.

To encourage them to develop for Android-powered wearables, Google and LG are promising “a low barrier to entry for developers,” and one analyst says that Google’s willingness to work with multiple hardware manufacturers—not just one, like Samsung—gives Google’s project an openness that “will help the Android Wear ecosystem build out faster, driving faster uptake.”

“The Android ecosystem has hundreds of thousands of developers already, versus a Tizen ecosystem where they’re trying to claim the virgin soil, and the question is who will be able to tap into the developers faster for innovation?” said Jefferson Wang, a wireless and mobility consultant at Philadelphia-based IBB Consulting Group.

As much incentive as Samsung may have to build and control an ecosystem of software and services of its own, like Tizen, Android has enough sway among developers to discourage Samsung from wanting to put all its eggs in one basket with Tizen, even just in the wearables market.

With smartphones, for instance, Samsung has made clear its intention to support multiple operating systems, including Android, Microsoft Corp.’s Windows phone and Samsung’s own proprietary platforms.

A spokesman for Samsung confirmed that the company would make an Android smartwatch, but said that “nothing has been decided yet” on timing.

As much as Samsung wants to dominate software and services for wearable devices, a strong opening move by Google may force Samsung to pare back its ambitions in wearables, says IBB’s Mr. Wang.

When Google releases the developer kit for Android Wear and shows developers what its software is capable of, “Samsung needs to crack it open and play with it, and see if there are any compelling reasons for them to switch strategies,” he says.

“Sure, Samsung has put its weight behind Tizen, but at the same time, once a developer community like Android, which is familiar with how Android is built and used, gets involved, that’s a huge existing base of developers.”